The developing field of strain-induced magnetization dynamics offers a
promising path toward efficiently controlling spins and phase transitions.
Understanding the underlying mechanisms is crucial in finding the optimal
parameters supporting the phononic switching of magnetization. Here, we present
an experimental and numerical study of time-resolved magnetization dynamics
driven by the resonant excitation of an optical phonon mode in iron garnets.
Upon pumping the latter with an infrared pulse obtained from a free-electron
laser, we observe spatially-varying magnetization precession, with its phase
depending on the direction of an external magnetic field. Our micromagnetic
simulations effectively describe the magnetization precession and switching in
terms of laser-induced changes in the crystal's magneto-elastic energy